Method and system for link aggregation across multiple switches

Abstract

One embodiment of the present invention provides a switch. The switch includes a forwarding mechanism and a control mechanism. During operation, the forwarding mechanism forwards frames based on their Ethernet headers. The control mechanism operates the switch in conjunction with a separate physical switch as a single logical switch and assigns a virtual switch identifier to the logical switch, wherein the virtual switch identifier is associated with a link aggregation group.

What is claimed is: 
     
       1. A switch, comprising: a forwarding module configurable to forward frames based on their Ethernet headers; a control module configurable to operate the switch in conjunction with a separate physical switch as a single logical switch and assign a virtual switch identifier to the logical switch, wherein the virtual switch identifier is associated with a link aggregation group; wherein the switch is a layer-2 switch capable of routing without requiring the network topology to be based on a spanning tree topology; and wherein the control module is further configurable to derive the virtual switch identifier based on an identifier for the link aggregation group. 
     
     
       2. The switch of  claim 1 , wherein the switch is a routing bridge configurable to operate in accordance with the Transparent Interconnection of Lots of Links (TRILL) protocol. 
     
     
       3. The switch of  claim 1 , wherein the control module is further configurable to derive the virtual switch identifier based on an identifier for the link aggregation group. 
     
     
       4. The switch of  claim 1 , wherein the virtual switch identifier is a virtual RBridge identifier in compliance with the TRILL protocol. 
     
     
       5. The switch of  claim 1 , wherein the link aggregation group is identified by a link aggregation group (LAG) identifier in accordance to the IEEE 802.1ax standard. 
     
     
       6. The switch of  claim 1 , wherein the switch is a router configurable to operate in accordance with the Internet Protocol (IP). 
     
     
       7. The switch of  claim 1 , wherein the switch is configurable to operate in accordance with the Multiprotocol Label Switching (MPLS) protocol. 
     
     
       8. A method, comprising:
 forwarding frames received at a switch based on their Ethernet headers; 
 operating the switch in conjunction with a separate physical switch as a single logical switch; 
 assigning a virtual switch identifier to the logical switch, wherein the virtual switch identifier is associated with a link aggregation group; 
 wherein the switch is a layer-2 switch capable of routing without requiring the network topology to be based on a spanning tree topology; and deriving the virtual switch identifier based on an identifier for the link aggregation group. 
 
     
     
       9. The method of  claim 8 , further comprising performing a layer-2 routing function in accordance with the Transparent Interconnection of Lots of Links (TRILL) protocol. 
     
     
       10. The method of  claim 8 , further comprising deriving the virtual switch identifier based on an identifier for the link aggregation group. 
     
     
       11. The method of  claim 8 , wherein the virtual switch identifier is a virtual RBridge identifier in compliance with the Transparent Interconnection of Lots of Links (TRILL) protocol. 
     
     
       12. The method of  claim 8 , wherein the link aggregation group is identified by a link aggregation group (LAG) identifier in accordance to the IEEE 802.1ax standard. 
     
     
       13. The method of  claim 8 , further comprising placing the virtual switch identifier in the header of an ingress frame. 
     
     
       14. The method of  claim 8 , further comprising notifying a separate physical switch about the reachability of a media access control (MAC) address associated with a device coupled to the switch. 
     
     
       15. The method of  claim 14 , wherein upon detecting a failure of a link between the device and the separate physical switch, the method further comprises disassociating the device from the virtual switch. 
     
     
       16. The method of  claim 14 , wherein upon detecting a failure of a link between the device and the switch, the method further comprises notifying the separate physical switch of the failure via an inter-switch communication channel. 
     
     
       17. The method of  claim 8 , further comprising advertising that the virtual switch is equivalent to both the switch and the separate physical switch, thereby facilitating multi-path routing to or from a device coupled to both switches. 
     
     
       18. The method of  claim 8 , wherein the switch is a router configurable to operate in accordance with the Internet Protocol (IP). 
     
     
       19. The method of  claim 8 , wherein the switch is configurable to operate in accordance with the Multiprotocol Label Switching (MPLS) protocol. 
     
     
       20. A switch means, comprising:
 a forwarding means for forwarding frames based on their Ethernet headers; 
 a control means for operating the switch in conjunction with a separate physical switch as a single logical switch and assigning a virtual switch identifier to the logical switch, wherein the virtual switch identifier is associated with a link aggregation group; 
 wherein the switch is a layer-2 switch capable of routing without requiring the network topology to be based on a spanning tree topology; and wherein the control means is further for deriving the virtual switch identifier based on an identifier for thr link aggregation group. 
 
     
     
       21. The switch means of  claim 20 , wherein the virtual switch identifier is a virtual RBridge identifier in compliance with the Transparent Interconnection of Lots of Links (TRILL) protocol; and
 wherein the link aggregation group is identified by a link aggregation group (LAG) identifier in accordance to the IEEE 802.1ax standard. 
 
     
     
       22. The switch means of  claim 20 , wherein the switch is a router configurable to operate in accordance with the Internet Protocol (IP). 
     
     
       23. The switch means of  claim 20 , wherein the switch is configurable to operate in accordance with the Multiprotocol Label Switching (MPLS) protocol.